In the Wideband Code Division Multiple Access (WCDMA) system, in order to realize anti-multipath interference and secrecy, signal is encrypted usually by using a pseudorandom code sequence, namely that the signal is scrambled. In the WCDMA system, the uplink usually uses a Gold code to realize the scrambling of signal, the effect of scrambling the physical channel of the uplink is to distinguish users, and scrambling the downlink can distinguish cells and channels. FIG. 1 is a schematic diagram of a scrambling code generator generating a pseudorandom sequence, in which MSB denotes the most significant bit, and LSB denotes the least significant bit; accordingly, at the base station side of the WCDMA system, the received signal sent by the user needs to be descrambled, and usually uses the Gold code for descrambling.
At the base station side of the WCDMA system, a receiver needs to process multiple users' information, and the scrambling code sequence used by each user and the phase at which the user is while descrambling are different; the simplest method is to design one scrambling code generator for each user, but its defect is that the expense of hardware is large; therefor, a method for time division multiplexing scrambling code is provided in a related art, but the method can only realize producing of one bit scrambling code each time so as to limit ability of processing the users in the case of the fixed system clock. In order to further improve the multiplexing efficiency to process more users in one system, a method for generating 2M-bit scrambling code in one time is provided in another related art, wherein, M=1, 2, 3, . . . , 32, and the method improves the ability of system processing users, but the method has the following defects:
firstly, the range of producing the scrambling code supported by the method is limited, that is, the method only supports producing 2, 4, 6, 8 . . . 64 bits scrambling code, but does not support producing odd bits scrambling code, and has a poor universality;
secondly, the method has a long system delay and low processing efficiency, for example, while producing 64 bits scrambling code, because the method can only produce 16 bits new scrambling code in one rotation, it needs to rotate four times to produce 64 bits scrambling code, thus processing one user will take 4-clock time, resulting in the long system delay and low processing efficiency.